Patterned fiber makes tiny scope

Researchers from the University of Sydney in Australia have found a way to make an endoscope that's a dozen times smaller than today's 10-millimeter versions. The technology should make it possible to image areas that are inaccessible today.

Endoscopes, which are made from bundles of optical fibers, are commonly used to provide images from inside the body. They are also used to provide images from other difficult-to-access areas like the insides of jet engines and nuclear reactors.

The researchers constructed a microscopic pattern of air channels within a single, four-fifths-of-a-millimeter-thick plastic fiber to provide an array of pixels capable of carrying an image from one end of the fiber to the other.

The photonic crystal fiber, which contains a square array of 112 air holes, is a plastic version of more common glass photonic crystal fiber. The device can provide an image by channeling light either through the polymer material between air holes or through the air holes.

The multichannel fibers could also be used as optical connectors between computer processors or from a computer processor to a memory module, according to the researchers. This would boost data transfer rates by allowing multiple channels per fiber rather than just one.

To make a practical endoscope the device needs to be fitted with a lens and engineered to provide illumination and image collection from the same fiber.

A practical endoscope could be produced within three years, according to the researchers. The work appeared in the January 26, 2004 issue of Optics Express.